Pulverized-fuel-burning apparatus



Nov. 20, 1928.

G P JACKSON .PULAVERIZED FUEL BURNING APPARATUS Filed F65. Z, 1924 Inn 5; %MW- ATTORNEYS Patented Nov. 20, 1928.

LttLQZQ UNITED TATES PATENT OFFEQE.

GEORGE 1?. JACKSON, OF FLUSHDTG, NEW YORK, ASSIGNOR TO COMBUSTION ENGINEER- ING CORPORATION, OF NEW YORK, N. Y., A CORPORATION 015 NEW YORK.

PULVERIZED-FUEL-BURNING APPARATUS.

Application filed February 29, 1924. Serial No. 695,969.

This invention relates to furnaces and is especially useful in Connection with furnaces for burning fuel in suspension, such as pulverized coal, on the stationary boilers.

5 One of the primary objects of my invention is to provide an improved manner of regulably admitting air for combustion, particularly in furnaces fired from more than one side, as for example, in furnaces fired from opposite sides.

Another of the objects of the invention has to do with an improved method of supporting 'the various portions of the refractory structure constituting the combustion chamber,

'whereby simplicity is obtained and expansion and contraction of the various parts provided for.

My invention also contemplates the novel construction, arrangement and combination of parts hereinafter more particularly to be pointed out.

How the foregoing, together with such other objects and advantages as may hereinafter appear, are incident to my invention,

is illustrated in the accompanying drawings wherein:

The figure is a vertical section through a furnace and boiler illustrating my improvements.

Referring now to the drawings the reference character A denotes the combustion chamber which is constructed in the following manner. A suitable supporting base or structure 7, preferably of concrete material is provided and upon this base the upright wall B forming the sides of the combustion chamber, is erected. For reasons which will hereinafter appear, the base 7 is in the nature of a double hopper in so far as its physical form is concerned. The bottom or bottom wall 8 of the combustion chamber is a refractory lining built up upon and supported by the base in the manner shown. It will be seen from inspection of the figure that the upright or side wall of the combustion chamber and the bottom thereof are carried on the base independently of one another whereby, in'the first place the load of the side wall is not imposed u on the bottom wall of the combustion cham r, and,'in the next place the bottom wall can expand or contract freely with respect to the 7 side wall. The top, roof or arch walls 9 of the combustion chamber, are supported from the metallic beam structure 10 independently ing sides of the combustion chamber.

of the 'side wall of the combustion chamber, with freedom -for expansion and contraction of the arches and the side wall, independently of one another.

The combustion chamber, as a whole, is rectangular in horizontal cross section, with a horizontal dimension (at least in the plane of the firing) greater than vertical dimenslon, i. e. the combustion chamber is longer than high and is of a width suitable to ac-' commpdate the number of burners required to deliver the quantities-of fuel it is desired to burn.

The upright wall is composed of an outer shell 11 and an inner shell 12, spaced apart so as to produce a hollow wall. 'At various points in the elevation of the side wall there are rows of tying-in bricks 13, dividing the space between the shells into horizontal compartments extending around the combustion chamber. These tying-in bricks secure the two shells together but with freedom for the two shells to expand and contract with reference to one another. The specific means for attaching the tying-in bricks to the outer shell is not shown as it forms no part of this invention, specifically considered, and it will suffice to point out that it is such as to permit vertical movement of the tying-in bricks with respect to the outer shell.

The pulverized coal is admitted simultaneously on opposite sides of the combustion chamber by rows of burners 14, arranged to admit the fuel, preferably with a portion of of the air required for combustion, in a downward direction adjacent the respective oppos- The number of burners varies with the particular installation.

The descending fuel and flame streams are ignited shortly after admission into the chamher, and continue to descend until their downward momentum is overcome by the draft,

whereupon the fuel and flame streams are turned: in toward the center and thence upwardly to the outlet 15 of the combustion chamber each stream taking a substantially U-shaped course, with the ascendin legs uniting in one general leg. The bend 1n the fuel I and flame streams is well above the bottom of the combustion chamber.

Since only a portion of the air required for combustion is supplied with the coal, the balance required is admitted through the holing from the point of inlet around the combustlon chamber through the respective compartments, entering the combustion chamber through the inlets 16. The damper controlled inlets 17 permit of regulation of the quantity of the air admitted to all of the compartments and to each of the compartments so that a very flexible system of airflcontrol is provided whereby the precise quantities of air needed to burn the fuel in the most effective manner are deliv ered in accordance with the needs of combustion as combustion proceeds. The air in passing in apposite directions through the wall to the point of inlet into the combustion chamber is heated by the absorption of heat from the walls.

tures-and also serves to protect the refractories from the temperature prevailing within the combustion chamber. Air, if desired, may also be admitted through the damper controlled inlets 18, it being possible to admit all of the air for combustion either through the inlets 17 or the inlets 18, or any proportion of the air required may be admitted throughboth. T

In the lower partof the combustion 'chamher I provide two water screens consisting of a pluralityof tubes 19 which pass out through the bottom of the combustion' chamber at about the middle portion thereof where they connect with a header 20. Each set of tubes 19 has such a header and such tubes are inclined and passed out through the upright wall for connection with a header 21 which header is connected into the circulation of the boilerb a plurality of risers 22, as shown. The headers 20 are conne uted by relatively large downcomer pipes 23 to thew'ater spaces or drums of the boiler. The function of the water screens is to create a cooled zone in the bottom of the combustion chamber through which recipitatingrefuse particles fall and by WhlCh they 7 This hasa beneficial effect on combustion and furnace tempera C and D each are cooled below the fusion point. This re fuse collects in the hoppers, of which there isione beneatheach fuel and flame stream and from which the refuse may be removed from, time to time substantially in the form 1 of the upright wall or to the feeder mecha nisms supplying the burners.

The boiler setting 26 is carried on th e beams 10 as-shown in a manner to be independent of the arches and the side wall.

The curvature in the pipes 23 takes care of expansion and contraction as between the two points, i. e. the headers 20 which are supported in the manner shown and the drums.

wardly simultaneously from opposite sides,'

and said combustion chamber having a bottom in the form of a double hopper the outer The tubes--19 expand from or con .tract; toward the middle ofthe combustion chamber because of the loose filling matewall portion of which is hollow, together with means for admitting a cooling medium into said hollow portion.

2'. In combination, a combustion chamber having a central outlet in the upper part thereof, means for admitting fuel to the chamber downwardly from opposite sides thereof so that each fuel and flame stream will describe a 'U-shaped course from the point of admission to the outlet, means for admitting air into an upright wall of the chamber 'at a. point intermediate the points of fuel admission and conducting the same through the wall and into the chamber.

In testimony whereof, I have hereunto signed my name GEonGE P. JACKSON. 

